/*
 *
 * Copyright (C) 2012 Walter Lütgenau
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 * 
 *      http://www.apache.org/licenses/LICENSE-2.0
 * 
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 * 
 */
package offset.nodes.client.editor.model;
import org.xml.sax.Attributes;
import org.xml.sax.ContentHandler;
import org.xml.sax.Locator;
import org.xml.sax.SAXException;

/*
 * Created on 03.09.2004
 *
 /* Copyright: CoCoNet Computer-Communication Networks GmbH 2004.
 * The copyright to the computer program(s) herein is the property of CoCoNet
 * Computer-Communication Networks GmbH. The program(s) may be used and/or
 * copied only with the written permission of CoCoNet Computer-Communication
 * Networks GmbH or in accordance with the terms and conditions stipulated in
 * the agreement/contract under which the program(s) have been supplied.
 */

import java.io.*;

/**
 * @author WalterL
 *
 */
public class PrintHandler implements ContentHandler {
	int level = 0;
	boolean afterCharacters = false;
	boolean afterStartElement = false;
	PrintStream out = null;
	
	public PrintHandler( OutputStream out ) {
		this.out = new PrintStream(out);
	}
	
	public PrintHandler() {
		this.out = System.out;
	}

	public void printIndent() {
		for (int i = 0; i < level; i++)
			out.print("\t");
	}

    /** Receive notification of the beginning of an element.
     *
     * <p>The Parser will invoke this method at the beginning of every
     * element in the XML document; there will be a corresponding
     * {@link #endElement endElement} event for every startElement event
     * (even when the element is empty). All of the element's content will be
     * reported, in order, before the corresponding endElement
     * event.</p>
     *
     * <p>This event allows up to three name components for each
     * element:</p>
     *
     * <ol>
     * <li>the Namespace URI;</li>
     * <li>the local name; and</li>
     * <li>the qualified (prefixed) name.</li>
     * </ol>
     *
     * <p>Any or all of these may be provided, depending on the
     * values of the <var>http://xml.org/sax/features/namespaces</var>
     * and the <var>http://xml.org/sax/features/namespace-prefixes</var>
     * properties:</p>
     *
     * <ul>
     * <li>the Namespace URI and local name are required when
     * the namespaces property is <var>true</var> (the default), and are
     * optional when the namespaces property is <var>false</var> (if one is
     * specified, both must be);</li>
     * <li>the qualified name is required when the namespace-prefixes property
     * is <var>true</var>, and is optional when the namespace-prefixes property
     * is <var>false</var> (the default).</li>
     * </ul>
     *
     * <p>Note that the attribute list provided will contain only
     * attributes with explicit values (specified or defaulted):
     * #IMPLIED attributes will be omitted.  The attribute list
     * will contain attributes used for Namespace declarations
     * (xmlns* attributes) only if the
     * <code>http://xml.org/sax/features/namespace-prefixes</code>
     * property is true (it is false by default, and support for a
     * true value is optional).</p>
     *
     * @param uri The Namespace URI, or the empty string if the
     *        element has no Namespace URI or if Namespace
     *        processing is not being performed.
     * @param localName The local name (without prefix), or the
     *        empty string if Namespace processing is not being
     *        performed.
     * @param qName The qualified name (with prefix), or the
     *        empty string if qualified names are not available.
     * @param atts The attributes attached to the element.  If
     *        there are no attributes, it shall be an empty
     *        Attributes object.
     * @exception org.xml.sax.SAXException Any SAX exception, possibly
     *            wrapping another exception.
     * @see #endElement
     * @see org.xml.sax.Attributes
     *
     */
    public void startElement(
    	String namespaceURI,
    	String localName,
    	String qName,
    	Attributes atts)
    	throws SAXException {
        if ( afterStartElement )
            out.print( ">");
        if ( !qName.equals("document"))
            out.println("");
    	printIndent();
    	out.print("<" + qName );
    	if ( atts != null ) {
    		for( int i=0; i<atts.getLength(); i++ ) {
    			out.print( " " + atts.getQName(i) + "=\"" + atts.getValue( i ) + "\"");
    		}
    	}
    	level++;
    	
    	afterStartElement = true;
    	afterCharacters = false;
    }

	/** Receive notification of character data.
	 *
	 * <p>The Parser will call this method to report each chunk of
	 * character data.  SAX parsers may return all contiguous character
	 * data in a single chunk, or they may split it into several
	 * chunks; however, all of the characters in any single event
	 * must come from the same external entity so that the Locator
	 * provides useful information.</p>
	 *
	 * <p>The application must not attempt to read from the array
	 * outside of the specified range.</p>
	 *
	 * <p>Note that some parsers will report whitespace in element
	 * content using the {@link #ignorableWhitespace ignorableWhitespace}
	 * method rather than this one (validating parsers <em>must</em>
	 * do so).</p>
	 *
	 * @param ch The characters from the XML document.
	 * @param start The start position in the array.
	 * @param length The number of characters to read from the array.
	 * @exception org.xml.sax.SAXException Any SAX exception, possibly
	 *            wrapping another exception.
	 * @see #ignorableWhitespace
	 * @see org.xml.sax.Locator
	 *
	 */
	public void characters(char[] ch, int start, int length)
		throws SAXException {
		String value = new String(ch);
		if ( afterStartElement )
		    out.print(">");
		out.write(value.getBytes(), start, length);
		
		afterCharacters = true;
		afterStartElement = false;
	}

	/** Receive notification of the end of a document.
	 *
	 * <p>The SAX parser will invoke this method only once, and it will
	 * be the last method invoked during the parse.  The parser shall
	 * not invoke this method until it has either abandoned parsing
	 * (because of an unrecoverable error) or reached the end of
	 * input.</p>
	 *
	 * @exception org.xml.sax.SAXException Any SAX exception, possibly
	 *            wrapping another exception.
	 * @see #startDocument
	 *
	 */
	public void endDocument() throws SAXException {
	}

	/** Receive notification of the end of an element.
	 *
	 * <p>The SAX parser will invoke this method at the end of every
	 * element in the XML document; there will be a corresponding
	 * {@link #startElement startElement} event for every endElement
	 * event (even when the element is empty).</p>
	 *
	 * <p>For information on the names, see startElement.</p>
	 *
	 * @param uri The Namespace URI, or the empty string if the
	 *        element has no Namespace URI or if Namespace
	 *        processing is not being performed.
	 * @param localName The local name (without prefix), or the
	 *        empty string if Namespace processing is not being
	 *        performed.
	 * @param qName The qualified XML 1.0 name (with prefix), or the
	 *        empty string if qualified names are not available.
	 * @exception org.xml.sax.SAXException Any SAX exception, possibly
	 *            wrapping another exception.
	 *
	 */
	public void endElement(
		String namespaceURI,
		String localName,
		String qName)
		throws SAXException {
		level--;
		if ( !afterCharacters && !afterStartElement) {
		    out.println("");
		    printIndent();
		}
		
		if ( afterStartElement )
		    out.print( "/>");
		else
		    out.print("</" + qName + ">");
		
		afterStartElement = afterCharacters = false;
		out.flush();
	}

	/** End the scope of a prefix-URI mapping.
	 *
	 * <p>See {@link #startPrefixMapping startPrefixMapping} for
	 * details.  This event will always occur after the corresponding
	 * {@link #endElement endElement} event, but the order of
	 * {@link #endPrefixMapping endPrefixMapping} events is not otherwise
	 * guaranteed.</p>
	 *
	 * @param prefix The prefix that was being mapping.
	 * @exception org.xml.sax.SAXException The client may throw
	 *            an exception during processing.
	 * @see #startPrefixMapping
	 * @see #endElement
	 *
	 */
	public void endPrefixMapping(String prefix) throws SAXException {
	}

	/** Receive notification of ignorable whitespace in element content.
	 *
	 * <p>Validating Parsers must use this method to report each chunk
	 * of whitespace in element content (see the W3C XML 1.0 recommendation,
	 * section 2.10): non-validating parsers may also use this method
	 * if they are capable of parsing and using content models.</p>
	 *
	 * <p>SAX parsers may return all contiguous whitespace in a single
	 * chunk, or they may split it into several chunks; however, all of
	 * the characters in any single event must come from the same
	 * external entity, so that the Locator provides useful
	 * information.</p>
	 *
	 * <p>The application must not attempt to read from the array
	 * outside of the specified range.</p>
	 *
	 * @param ch The characters from the XML document.
	 * @param start The start position in the array.
	 * @param length The number of characters to read from the array.
	 * @exception org.xml.sax.SAXException Any SAX exception, possibly
	 *            wrapping another exception.
	 * @see #afterCharacters
	 *
	 */
	public void ignorableWhitespace(char[] ch, int start, int length)
		throws SAXException {
	}

	/** Receive notification of a processing instruction.
	 *
	 * <p>The Parser will invoke this method once for each processing
	 * instruction found: note that processing instructions may occur
	 * before or after the main document element.</p>
	 *
	 * <p>A SAX parser must never report an XML declaration (XML 1.0,
	 * section 2.8) or a text declaration (XML 1.0, section 4.3.1)
	 * using this method.</p>
	 *
	 * @param target The processing instruction target.
	 * @param data The processing instruction data, or null if
	 *        none was supplied.  The data does not include any
	 *        whitespace separating it from the target.
	 * @exception org.xml.sax.SAXException Any SAX exception, possibly
	 *            wrapping another exception.
	 *
	 */
	public void processingInstruction(String target, String data)
		throws SAXException {
	}

	/** Receive an object for locating the origin of SAX document events.
	 *
	 * <p>SAX parsers are strongly encouraged (though not absolutely
	 * required) to supply a locator: if it does so, it must supply
	 * the locator to the application by invoking this method before
	 * invoking any of the other methods in the ContentHandler
	 * interface.</p>
	 *
	 * <p>The locator allows the application to determine the end
	 * position of any document-related event, even if the parser is
	 * not reporting an error.  Typically, the application will
	 * use this information for reporting its own errors (such as
	 * character content that does not match an application's
	 * business rules).  The information returned by the locator
	 * is probably not sufficient for use with a search engine.</p>
	 *
	 * <p>Note that the locator will return correct information only
	 * during the invocation of the events in this interface.  The
	 * application should not attempt to use it at any other time.</p>
	 *
	 * @param locator An object that can return the location of
	 *                any SAX document event.
	 * @see org.xml.sax.Locator
	 *
	 */
	public void setDocumentLocator(Locator locator) {
	}

	/** Receive notification of a skipped entity.
	 *
	 * <p>The Parser will invoke this method once for each entity
	 * skipped.  Non-validating processors may skip entities if they
	 * have not seen the declarations (because, for example, the
	 * entity was declared in an external DTD subset).  All processors
	 * may skip external entities, depending on the values of the
	 * <code>http://xml.org/sax/features/external-general-entities</code>
	 * and the
	 * <code>http://xml.org/sax/features/external-parameter-entities</code>
	 * properties.</p>
	 *
	 * @param name The name of the skipped entity.  If it is a
	 *        parameter entity, the name will begin with '%', and if
	 *        it is the external DTD subset, it will be the string
	 *        "[dtd]".
	 * @exception org.xml.sax.SAXException Any SAX exception, possibly
	 *            wrapping another exception.
	 *
	 */
	public void skippedEntity(String name) throws SAXException {
	}

	/** Receive notification of the beginning of a document.
	 *
	 * <p>The SAX parser will invoke this method only once, before any
	 * other methods in this interface or in {@link org.xml.sax.DTDHandler
	 * DTDHandler} (except for {@link #setDocumentLocator
	 * setDocumentLocator}).</p>
	 *
	 * @exception org.xml.sax.SAXException Any SAX exception, possibly
	 *            wrapping another exception.
	 * @see #endDocument
	 *
	 */
	public void startDocument() throws SAXException {
	}

	/** Begin the scope of a prefix-URI Namespace mapping.
	 *
	 * <p>The information from this event is not necessary for
	 * normal Namespace processing: the SAX XML reader will
	 * automatically replace prefixes for element and attribute
	 * names when the <code>http://xml.org/sax/features/namespaces</code>
	 * feature is <var>true</var> (the default).</p>
	 *
	 * <p>There are cases, however, when applications need to
	 * use prefixes in character data or in attribute values,
	 * where they cannot safely be expanded automatically; the
	 * start/endPrefixMapping event supplies the information
	 * to the application to expand prefixes in those contexts
	 * itself, if necessary.</p>
	 *
	 * <p>Note that start/endPrefixMapping events are not
	 * guaranteed to be properly nested relative to each-other:
	 * all startPrefixMapping events will occur before the
	 * corresponding {@link #startElement startElement} event,
	 * and all {@link #endPrefixMapping endPrefixMapping}
	 * events will occur after the corresponding {@link #endElement
	 * endElement} event, but their order is not otherwise
	 * guaranteed.</p>
	 *
	 * <p>There should never be start/endPrefixMapping events for the
	 * "xml" prefix, since it is predeclared and immutable.</p>
	 *
	 * @param prefix The Namespace prefix being declared.
	 * @param uri The Namespace URI the prefix is mapped to.
	 * @exception org.xml.sax.SAXException The client may throw
	 *            an exception during processing.
	 * @see #endPrefixMapping
	 * @see #startElement
	 *
	 */
	public void startPrefixMapping(String prefix, String uri)
		throws SAXException {
	}

	//
}

